20131307761 has 2 divisors, whose sum is σ = 20131307762. Its totient is φ = 20131307760.

The previous prime is 20131307737. The next prime is 20131307969. The reversal of 20131307761 is 16770313102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13946429025 + 6184878736 = 118095^2 + 78644^2 .

It is a cyclic number.

It is not a de Polignac number, because 20131307761 - 2⁹ = 20131307249 is a prime.

It is not a weakly prime, because it can be changed into another prime (20131302761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10065653880 + 10065653881.

It is an arithmetic number, because the mean of its divisors is an integer number (10065653881).

Almost surely, 2^20131307761 is an apocalyptic number.

It is an amenable number.

20131307761 is a deficient number, since it is larger than the sum of its proper divisors (1).

20131307761 is an equidigital number, since it uses as much as digits as its factorization.

20131307761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 31.

The spelling of 20131307761 in words is "twenty billion, one hundred thirty-one million, three hundred seven thousand, seven hundred sixty-one".